1. Field
Embodiments described herein relate to a charge/discharge determining apparatus and computer-readable medium.
2. Description of the Related Art
In recent years, various kinds of natural energy have come to serve as major power supply sources like power plants.
However, the output power of natural energy varies to a large extent. For example, the generated power is very low when the weather is bad (in the case of photovoltaic power generation) or when no wind blows (in the case of wind power generation). When the power supplied from natural energy power supply sources drops rapidly, the actual power supply amount of a power network becomes much smaller than a planned value.
In such a case, to increase the actual power supply amount to the planned value, it is necessary to change the power supply amount of a power plant via a power supply command center of an electric power company. To change the power supply amount of the power plant, it is necessary to change the turbine rotation speed. However, it takes a certain time from issuance of a rotation change command to establishment of a new turbine rotation speed. The actual power supply amount is smaller than the planned value during such a transition period, possibly leading to a power failure.
To prevent such an event, the power decrease should be compensated for by power that is supplied from a battery system.
Where plural kinds of battery systems exist, the individual systems are different from each other in residual electric energy. Therefore, for example, the residual electric energy of a selected battery system may be lower than electric energy that is necessary to compensate for the power decrease until the turbine rotation speed reaches the new value. That is, even if switching is made to a battery system, a power failure or the like may still occur. Thus, the power network remains unstable.